Polymeric foam and scrim sheathings

ABSTRACT

A sheathing adapted to be fastened to at least one wall supporting structure comprises at least two layers. The first layer comprises a polymeric foam layer. The second layer comprises a polymeric scrim and is located adjacent to the first layer. The second layer reinforces its periphery so as to inhibit the failure of the scrim. The reinforced periphery may include a selvage tuck or a folded-edge.

FIELD OF THE INVENTION

[0001] The present invention relates generally to sheathings that areused in structures and, more particularly, to polymeric foam sheathingmaterials that are used in prefabricated housing and site built housing.

BACKGROUND OF THE INVENTION

[0002] There are different commercial sheathings that are used in theconstruction of buildings. Sheathings include materials that span theframe supports of buildings. Some of the commercial products that havebeen used as sheathing include thin composite laminations, fiberboard,orientated strand board (OSB) and plywood. Some of these productsprovide structural strength, durability and/or rigidity. These products,however, have disadvantages such as being heavy and difficult toinstall, providing little insulation and/or having poor moistureresistance.

[0003] There are other commercial products that are available assheathing. For example, polyisocyanurate foam, extruded polystyrenefoam, and molded expanded polystyrene (EPS) foam. These existing foamedmaterials generally have advantages such as increased insulation andeasier handling. These existing foamed materials, however, havedisadvantages such as their lack of strength as measured by windresistance. This is shown, for example, by their failures to withstand100 miles per hour winds when installed behind exterior facing such assiding or brick. Wind resistance may cause problems such as fracturing,cracking and/or edge pull out of the sheathing from the fasteners.During the pulling of the edge of the material, the fastener generallyremains, but the sheathing is pulled away.

[0004] Existing foam sheathing is still susceptible to damage at thebuilding site prior to installation. This problem is further evidentwhen, for example, delays occur in the installation and/or theinstallation occurs in extreme weather conditions. One common example ofdamage that may occur is when a piece breaks off from a remainder of thesheathing during the process of installation or by vandalism afterinstallation at the building site before being covered with an exteriorfacing such as siding, brick, or stucco.

[0005] Accordingly, a need exists for a sheathing that overcomes theabove-noted shortcomings associated with existing sheathing.

SUMMARY OF THE INVENTION

[0006] According to one embodiment of the present invention, a sheathingadapted to be fastened to at least one wall supporting structurecomprises at least two layers. The first layer comprises a polymericfoam layer. The second layer comprises a polymeric scrim, and is locatedadjacent to the first layer. The second layer has means for reinforcingits periphery so as to inhibit failure of the sheathing. The reinforcingmeans may include a selvage tuck or a folded-over edge.

[0007] According to another embodiment of the present invention, asheathing adapted to be fastened to at least one wall supportingstructure comprises at least three layers. The first layer comprises apolymeric foam layer, while the second layer comprises a polymericcross-woven scrim. The second layer has means for reinforcing itsperiphery so as to inhibit failure of the sheathing. The third layercomprises an impact polystyrene and is located between the first and thesecond layers.

[0008] According to one method of the present invention, a sheathing isprovided that comprises at least two layers. The first layer comprises apolymeric foam layer. The second layer comprises a polymeric scrim andis located adjacent to the first layer. The second layer has means forreinforcing its periphery so as to inhibit failure of the sheathing. Thesheathing is installed to a wall supporting structure.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 shows a side view of a two-layer sheathing according to oneembodiment of the present invention.

[0010]FIG. 2 shows a side view of a three-layer sheathing according toanother embodiment of the present invention.

[0011]FIG. 3 shows a side view of a four-layer sheathing according toanother embodiment of the present invention.

[0012]FIG. 4 shows a side view of a five-layer sheathing according toyet another embodiment of the present invention.

[0013]FIG. 5 shows a side view of a seven-layer sheathing according to afurther embodiment of the present invention.

[0014]FIG. 6 shows a cut-away perspective view of a five-layer sheathingfastened to a wall supporting structure according to one embodiment ofthe present invention.

[0015]FIG. 7 shows a schematic flow diagram of an overall sequence ofoperations according to one process involved in the manufacture of athree-layer sheathing such as that shown in FIG. 2.

[0016] While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and will herein be described in detail. Itshould be understood, however, that it is not intended to limit theinvention to the particular forms disclosed but, on the contrary, theintention is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the invention as defined by theappended claims.

DESCRIPTION OF SPECIFIC EMBODIMENTS

[0017] Turning now to the drawings and referring initially to FIG. 1, atwo-layer sheathing 10 is shown according to one embodiment of thepresent invention. The sheathings of the present invention, includingsheathing 10, are adapted to be fastened to a wall supporting structure.On a building, sheathings are typically covered by an exterior facingsuch as siding, brick or stucco. The sheathing 10 of FIG. 1 comprises apolymeric scrim layer 12 and a polymeric foam layer 14. The polymericscrim layer 12 of the present invention provides additional strength anddurability to the polymeric foam layer 14.

[0018] Polymeric Scrim Layer

[0019] The polymeric scrim layer 12 may be made of woven material ornon-woven material. Woven material is generally defined as long fibersthat are intertwined to produce a material. Non-woven material isgenerally defined as randomly joined fibers that are bonded or pressedtogether by adhesive or other means. The randomly joined fibers thatform non-woven material are typically shorter than those used in formingwoven material. The woven material is generally preferred because itprovides an excellent strength to weight ratio that is desirable inwind-resistant applications.

[0020] One type of woven scrim that may be used in polymeric scrim layer12 is a scrim that runs in the machine direction (MD) and the weft ortransverse direction (TD). This is commonly referred to as a cross-wovenscrim. This type of woven scrim may be the type that is commonly used inapplications such as carpet backing. One type of scrim is a 7×4polypropylene scrim. Other scrim counts include 16×5, 10×5 and 12×4. Itis also contemplated that other scrim counts may be used in forming thepolymeric scrim layer of the present invention.

[0021] The polymeric scrim layer 12 may be made of materials such aspolyolefins, polyesters and nylons. Polyolefins that may be used in thepolymeric scrim layer 12 include polypropylenes or polyethylenes. Theterm “polypropylene” as used herein includes polymers of propylene orpolymerizing propylene with other aliphatic polyolefins, such asethylene, 1-butene, 1-pentene, 3-methyl-1-butene, 4-methyl-1-pentene,4-methyl-1-hexene, 5-methyl-1-hexene and mixtures thereof. Polypropylenenot only includes homopolymers of propylene, but also propylenecopolymers comprised of at least 50 mole percent (preferably at least 70mole percent) of a propylene unit and a minor proportion of a monomercopolymerizable with propylene and blends of at least 50 percent byweight of the propylene homopolymer with another polymer.

[0022] The term “polyethylene” as used herein includes low densitypolyethylene (LDPE), medium density polyethylene (MDPE), high densitypolyethylene (HDPE), very low density polyethylene (VLDPE), linear lowdensity polyethylene (LLDPE), metallocene-catalyzed linear low densitypolyethylene (mLLDPE) and combinations thereof.

[0023] LDPE is generally defined as an ethylenic polymer having aspecific gravity of from about 910 to about 925 kg/m³. MDPE is generallydefined as an ethylenic polymer having a specific gravity between theLDPEs and the HDPEs (i.e., from about 925 to about 940 kg/m³). The highdensity polyethylene (HDPE) of the present invention has a specificgravity of from about 940 to about 970 kg/m³. The term polyethylene asused herein includes homopolymers of ethylene and copolymers comprisedof at least 50 mole percent of a ethylene unit (preferably at least 70mole percent) and a minor (i.e., less than 50%) proportion of a monomercopolymerizable with the ethylene unit. The term LDPE as used hereinalso includes physical blends of two or more different homopolymers thatare classified as LDPEs. Similarly, the term MDPE and HDPE may alsoinclude blends of two or more different homopolymers classified as MDPEsand HDPEs, respectively.

[0024] The VLDPE resins have densities ranging from about 880 to about912 kg/m³, more commonly from about 890 to about 910 kg/m³, and meltindices of from about 0.5 to about 5 g/10 min., and from about 1 toabout 3 g/10 min.

[0025] The LLDPE of the present invention generally has from about 1 toabout 20, preferably from about 1 to about 10 weight percent of saidhigher alpha olefin monomer copolymerized therein. In addition, thealpha olefin monomer employed in the ethylenic copolymer may be selectedfrom the group consisting of 1-butene, 3-methyl-1-butene,3-methyl-1-pentene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-hexene,1-octene and 1-decene. The LLDPE resins that may be used in the presentinvention have densities ranging from about 890 to about 940 kg/m³, morecommonly from about 900 to about 930 kg/m³, and a melt index (I₂) offrom about 1 to about 10 g/10 min. as determined by ASTM D1238.

[0026] The metallocene-catalyzed polyethylene (mLLDPE) is a polymerhaving a low polydispersity. The low polydispersity polymer may beprepared from a partially crystalline polyethylene resin that is apolymer prepared with ethylene and at least one alpha olefin monomer,e.g., a copolymer or terpolymer. The alpha olefin monomer generally hasfrom about 3 to about 12 carbon atoms, preferably from about 4 to about10 carbon atoms, and more preferably from about 6 to about 8 carbonatoms. The alpha olefin comonomer content is generally below about 30weight percent, preferably below about 20 weight percent, and morepreferably from about 1 to about 15 weight percent. Exemplary comonomersinclude propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-pentene,4-methyl-1-pentene, 1-octene, 1-decene, and 1-dodecene.

[0027] The low polydispersity polymer has a density of from about 880 toabout 940 kg/M³. The polydispersity polymer should have a molecularweight distribution, or polydispersity, (M_(w)/M_(n), “MWD”) within therange of from about 1 to about 4, and more typically from about 2 toabout 3. The melt flow ratio (MFR) of these polymers, defined as I₂₀/I₂and as determined in accordance to ASTM D1238, is generally from about12 to about 22 and typically from about 14 to about 20. The melt index(MI), defined as the I₂ value, should be in the range of from about 0.5to about 10 g/10 min. and typically from about 1 to about 5 g/10 min. asdetermined by ASTM D1238.

[0028] An example of a “polyester” includes a polyester resin which is apolycondensation product of a dicarboxylic acid with a dihydroxyalcohol. An example of a “polyethylene terephthalate” includes apolyester resin made from ethylene glycol and terephthalic acid. Anexample of a “nylon” is a polyamide polymer that is characterized by thepresence of the amide group (—CONH).

[0029] The polymeric scrim layer 12 has means for reinforcing itsperiphery so as to inhibit the failure of the sheathing. The polymericscrim layer may have a reinforced periphery via a selvage tuck or afolded-over edge.

[0030] Selvage tucking is generally defined as weaving or laminating theperiphery of the sheathing so as to inhibit failure of the sheathing.One example of the sheathing failing is when the periphery of thesheathing is pulled out from the fastener attaching the sheathing to awall supporting structure (see, e.g., wall supporting structure 22 ofFIG. 6). One type of selvage type that can be used is a lenolatchselvage tuck. The lenolatch selvage tuck incorporates a lenolatch cordthat locks fill yarns so as to prevent or inhibit the scrim fromunraveling. The selvage tuck is preferably located on at least twoopposing portions of the periphery of the polymeric scrim layer. It ispreferred that the selvage tuck extends along two entire sides of thepolymeric scrim layer. More specifically, the selvage tuck is preferablylocated near two opposing edge portions. It is contemplated that theselvage tuck may be located on all sides of the polymeric scrim layer.

[0031] It is contemplated that additional polymeric scrim layer(s) canbe added to the sheathing. For example, the sheathing may includepolymeric scrim layers on opposing sides of the polymeric foam layer.

[0032] Polymeric Foam Layer

[0033] The polymeric foam layer 14 is located adjacent to the scrimlayer 12 in FIG. 1. The polymeric foam layer 14 may be made from alkenylaromatic resins, such as polystyrenic resin(s), and polyesters such aspolyethylene terephthalates. The term “alkenyl aromatic polymer” as usedherein includes polymers of aromatic hydrocarbon molecules that containan aryl group joined to an olefinic group with only double bonds in thelinear structure. The polymeric foam layer 14 may also be made frompolyolefinic resins such as LDPEs, HDPEs, LLDPEs, and the like. Thepolymeric foam layer 14 is preferably made from a polystyrenic resin(s),such as a general purpose polystyrene, because of economicalconsiderations at the present time. The polymeric foam layer 14,however, may be made from other polystyrenic resins such as impactpolystyrenes. The impact polystyrenes that are generally used includemedium impact polystyrenes and high impact polystyrenes. The polymericfoam layer 14 may also be made from a combination of virgin and/orreprocessed material.

[0034] The polymeric foam layer 14 and the polymeric scrim layer 12 maybe bonded by attaching, adhering, fusing or the like. For example, thepolymeric foam layer 14 and the polymeric scrim layer 12 may bethermally bonded to each another depending on the selected materials forforming the layers 12 and 14. Thermal bonding may be accomplished byconventional methods, such as a flameless air torches, heated rolls,radiant heaters and infrared heating.

[0035] Adhesive and Other Layers

[0036] Alternatively, the polymeric foam layer 14 and the polymericscrim layer 12 may be attached with an adhesive layer. This is shown inFIG. 2 where sheathing 30 includes a polymeric scrim layer 12, apolymeric foam layer 14 and an adhesive layer 16. The optional adhesivelayer 16 is located between the polymeric scrim layer 12 and thepolymeric foam layer 14. One type of adhesive that may be used isethylene vinyl acetate (EVA). For example, modified EVAs such as BYNEL®made by DuPONT® or Plexar® made by Equistar Chemicals may be used. Thesemodified EVAs have melt indices generally from about 6.4 to about 25g/10 min. as measured by ASTM D1238 and densities generally from about0.923 to about 0.947 g/cm³ as measured by ASTM D1505. BYNEL® is anadhesive that is designed to bond materials that would not ordinarilyadhere to each other.

[0037] Other adhesives that may be used include block copolymers thatcomprise polymeric regions of styrene-rubber-styrene. For example,KRATON® made by Shell® Chemical Company may be used. Other adhesives arecontemplated in the present invention to bond the polymeric scrim layer12 to the polymeric foam layer 14.

[0038] Additional layers are contemplated in the sheathings of thepresent invention. For example, FIGS. 3, 4 and 5 depict a four-layersheathing, a five-layer sheathing and a seven-layer sheathing,respectively. Referring specifically to FIG. 3, sheathing 40 includes apolymeric scrim layer 12, a polymeric foam layer 14, an adhesive layer16 and an impact polystyrenic layer 18. The polystyrenic layer 18 ispreferably made from a high impact polystyrene because of its desiredstiffness. The polystyrenic layer 18 may be biaxially orientated so asto provide additional durability and flexibility.

[0039]FIG. 4 depicts a sheathing 50 that is similar to the sheathing 40of FIG. 3, except that the sheathing 50 includes an additional impactpolystyrenic layer 18. Sheathing 60 of FIG. 5 comprises the same fivelayers of the sheathing 50 of FIG. 4. The sheathing 60 of FIG. 5,however, also comprises two additional layers. Specifically, thesheathing 60 includes an additional adhesive layer 16 and a polymericfilm layer 20. To provide additional strength and durability, thepolymeric film layer 20 may be made from a polyolefin(s) such aspolypropylene.

[0040] Other layers are contemplated for the sheathings of the presentinvention. For example, the sheathings of the present invention mayinclude radiant barrier layers or flame retardant layers.

[0041] Properties of the Sheathing

[0042] The sheathings of the present invention generally have a flexuralstrength of at least 125 lbs./in.², preferably at least 175 lbs./in.²and most preferably at least 200 lbs./in.² as measured by ASTM D1307.The sheathings of the present invention have excellent strength so as toprovide resistance to high winds. The sheathings of the presentinvention preferably satisfy the structural design requirements as setforth in the H.U.D. Guide for Manufactured Home Standards Programs(9^(th) edition, December 1994) for Wind Zone II conditions (a designwind speed of 100 miles per hour) taken from §3280.305(c) of the FederalRegister. The sheathings also preferably satisfy the structural designrequirements as set forth in H.U.D. Guide for Manufactured HomeStandards Programs (9^(th) edition, December 1994) for Wind Zone IIIconditions (a design wind speed of 110 mph) taken from §3280.305(c) ofthe Federal Register.

[0043] The sheathings of the present invention may be formed into anumber of shapes. For example, the sheathing may be a flat sheet or afolded or hinged board (typically referred to as a fanfolded sheathing).The fanfold sheathing is designed to unfold at its hinges and includes anumber of individual panels.

[0044] The sheathings of the present invention may be manufactured in avariety of sizes. Popular sizes used in the housing market include a 4foot by 7 foot (4′×7′), 4′×7 ½′, 4′×8′ and 4′×9′ flat sheets. Otherpopular size in the housing market include a 4′×50 ′ fanfolded sheathingwhich includes a number of individual panels. If a fanfolded sheathingis used, it is preferred to have cross-members in the wall supportingstructure for which the fanfolded sheathing may be attached.

[0045] The thickness of the sheathings may also vary, but is generallyfrom about ⅛ of an inch to about 2 inches as measured by ASTM D1622-88.The thickness of the sheathing is typically from about ¼ of an inch toabout 1 inch. Popular thicknesses of the sheathing include about ¼,about {fraction (5/16)}, about ⅜, about ½ and about ¾ of an inch.

[0046] The layers of the sheathings typically vary in their respectiveweight percent relative to each other. The sheathings generally comprisefrom about 2 wt. % to about 30 wt. % of the polymeric scrim layer(s) 12.The sheathings generally comprise from about 25 wt. % to about 99 wt. %of the polymeric foam layer(s) 14. The sheathings generally comprisefrom 0 wt. % to about 15 wt. % of the adhesive layer(s) 16. It iscontemplated that the remainder of the sheathings may include otheroptional layers. The sheathings generally comprise from 0 wt. % to about50 wt. % of the impact polystyrenic layer(s) 18 and from 0 wt. % toabout 50 wt. % of the polymeric film layer(s) 20.

[0047] The sheathings preferably comprise from about 2 to about 25 wt.%, and most preferably from about 4 wt. % to about 20 wt. % of thepolymeric scrim layer(s) 12. The sheathings preferably comprise fromabout 30 to about 95 wt. %, and most preferably from about 40 wt. % toabout 90 wt. % of the polymeric foam layer(s) 14. Preferably, thesheathings comprise from about 1 to about 10 wt. %, and most preferablyfrom about 1 wt. % to about 7 wt. % of the adhesive layer(s) 16. Thesheathings preferably comprise from about 5 to about 35 wt.%, and mostpreferably from about 5 wt. % to about 30 wt. % of the impactpolystyrenic layer(s) 18. The sheathings preferably comprise from 0 toabout 25 wt. %, and most preferably from 0 wt. % to about 20 wt. % ofthe polymeric film layer(s) 20.

[0048] The sheathings of the present invention may be used in variousbuildings such as prefabricated housing (also referred to asmanufactured housing) and site built housing. The sheathing may beinstalled to a wall supporting structure. One example is shown in FIG. 6where a sheathing 52 is installed to a plurality of wall supportingstructures 22. The sheathing 52 a has been cut-away to depict thevarious layers 12, 14, 16 and 18, while sheathing 52 b has not beencut-away in FIG. 6. FIG. 6 also shows siding 56 being located on anexterior surface of the sheathing 52.

[0049] The sheathing 52 of FIG. 6 may be installed to the plurality ofwall supporting structure 22 by the use of fasteners (not shown). Thefastener may be a mechanical fastener such as a staple or nail. Thesheathing 52 preferably has at least two opposing reinforced portions ofits peripheries (e.g., selvage tuck). Two opposing reinforced portionsextend along entire opposing sides and are approximately parallel to oneof the plurality of wall supporting structures 22. The opposingreinforced peripheries 54 are located on the vertical sides of thesheathing 52 in FIG. 6. The general location of one of the opposingreinforced portions 54 b is shown on sheathing 52 b in FIG. 6, while theother opposing reinforced portion has been cut-away in sheathing 52 band, thus, is not shown in FIG. 6. Likewise, only one of the opposingreinforced portions 54 a is shown on sheathing 52 a.

[0050] It is contemplated that the sheathing of the present inventionmay be used in a roofing application to provide additional strength, toresist wind uplift and to provide durability that minimizes breakageduring handling and installation. The sheathing may be used as anunderlayment for low slope roofs.

PROCESS OF THE PRESENT INVENTION

[0051] According to one process of the present invention, a polymericweb of foam is provided to form the polymeric foam layer. The processmay use a single twin screw extruder or a tandem foam extrusion line.For example, the process begins by loading pellets of a polymericresin(s) such as polystyrenic foam resin. The polymeric resins in theirsolid form are added into an extrusion hopper.

[0052] A nucleating agent (also referred to as cell size control agent)or combination of such nucleating agents may be employed in the processof the present invention for advantages such as their capability forregulating cell formation and morphology. The amount of nucleating agentto be added depends upon the desired cell size, the selected blowingagent and the density of the polymeric composition. Known nucleatingagents such as talc, mixtures of sodium bicarbonate and citric acid, andthe like may be employed in the present invention.

[0053] It is contemplated that stability control agent(s) may also beadded to the polymeric resin(s), including conventional stabilitycontrol agents. Some examples of stability control agents that may beused include, but are not limited to, glycerol monostearate, saturatedhigher fatty acid amides and glycerol monoester of a C₂₀-C₂₄ fatty acid.

[0054] If desired, fillers, colorants, light and heat stabilizers,plasticizers, chemical blowing agents, flame retardants, foamingadditives and plastic compounding agents may be added to the polymericcomposition. The polymeric composition comprises the polymeric resinand, if added, the nucleating agent, the stability control agent andadditives. The polymeric composition is conveyed through a feed zone ofthe extruder and heated at a temperature sufficient to form a polymericmelt.

[0055] A physical blowing agent may be added at the injection port areaof the extruder in an appropriate ratio to the target density. Theselected blowing agent may be any type that is capable of producing foamwith the selected resin. Some examples of blowing agents includephysical blowing agents such as halocarbons, hydrocarbons orcombinations thereof. Examples of these include commercially availablehydrofluorocarbons, such as HFC-152a and HFC-134a,hydrochlorofluorocarbons, such as HCFC-22 or HCFC-142b, and the C₃-C₆hydrocarbons. Other types of blowing agents include carbon dioxide. Thepolymeric composition and the selected blowing agent are thoroughlymixed within the extruder in a mixing zone and subsequently cooled in acooling zone. The cooled polymeric-blowing agent melt is extrudedthorough a die.

[0056] One method of the present invention for making a three-layersheathing is shown in a schematic flow diagram in FIG. 7. In the processof FIG. 7, the polymeric foam is extruded from an extruder 70 through around die 72. After exiting the round die 72, the extrudate expands whenentering a lower pressure region (e.g., the atmosphere) and forms apolymeric web of foam. The polymeric web of foam is stretched over asizing mandrel 74 to size and then is slit to form the web of foam. Thepolymeric web of foam will eventually be used in forming the polymericfoam layer 14.

[0057] At least one of the outer surfaces of the polymeric web of foamis typically cooled so as to form a “skin.” The skin is typically abouta few thousands (or a few mils) thick, but may vary depending on thecooling employed. The skin provides additional strength and alsoprovides a smoother surface that is more aesthetically pleasing to aconsumer if the polymeric layer is visible to the customer. It iscontemplated that cooling methods may be accomplished by using air andwater. The skinning may be performed, for example, by stretching thepolymeric foam of web 76 over the sizing mandrel 74 with optionalcooling wherein either surface of the polymeric foam of web 76 iscooled. It is contemplated that one or more of the surfaces of thepolymeric web of foam may be cooled.

[0058] The polymeric foam web 76 proceeds to travel around a S-wrap ofrollers 78 a-c in which roller 78 a is an idler roller and rollers 78 band 78 c are driven or pull rollers. The driven rollers 78 b, 78 cassist in moving the polymeric foam web 76 through the process of thepresent invention. The polymeric foam web 76 proceeds between two drivenrollers 80 a,b. Driven rollers 80 a,b assist in maintaining a consistentsurface on which a web of adhesive 82 a is added via an adhesive coatingor a laminating machine 82; The adhesive machine 82 may be anyconventional machine that is capable of applying the adhesive web 82 ato the polymeric foam web 76. The adhesive machine 82 may coextrude theweb of adhesive 82 a with a second web, such as a web of impactpolystyrene (not shown).

[0059] At the about the same time, a web of scrim 84 a is added via aroll unwind cart system 84. The cart system 84 may include an edgealignment system to properly align the web of scrim 84 a to thepolymeric foam web 76. After exiting the driven rollers 80 a,b, thepolymeric foam web 76, the web of adhesive 82 a and the web of scrim 84a form a sheathing web 86.

[0060] It is contemplated that the sheathing web 86 may be processed toinclude printing on one or more surfaces or other treatments. Theprocess of FIG. 7 includes an optional printer 88 that prints on onesurface of the sheathing web 86. It is contemplated that the printingmay occur on the polymeric foam web 76 before the webs of adhesive andscrim are added to the polymeric foam web 76. The sheathing web 86proceeds around a series of rollers 90 a-90 d and then to an optionaledge trim system 92. The edge trim system assists in sizing thesheathing web 86 to be used in forming the sheathing of the presentinvention.

[0061] As shown in FIG. 7, the sheathing web 86 proceeds through anoptional perforating creasing machine 94. The perforating creasingequipment 94 may include any conventional equipment that is capable offolding the sheathing web 86 of the present invention into a fanfoldsheathing web. Of course, if flat sheathing is desired the creasingequipment 94 should not be included in the process. A perforatingmachine, however, may be used in producing a flat sheathing. Thesheathing web is then cut to a desired dimension by shearing equipment96. The shearing equipment 96 may be any equipment capable of cuttingthe sheathing web 86 into desired dimensions. It is also contemplatedthat other finishing operations may occur such as stacking, counting,packaging and trimming. It is also contemplated that variousmeasurements may be taken throughout the process to ensure consistentmeasurements.

[0062] According to a second process of the present invention (notshown), additional layers may be added in forming other sheathings, suchas those described above. For example, a machine (not shown) may beadded to the process of FIG. 7 that is adapted to add an additionalimpact polystyrenic web to the polymeric web of foam.

EXAMPLES Example 1

[0063] Negative wind pressure load tests were conducted on samples ofsheathing (“Sheathing 1”) using a 2×4 (1½ inches×3½ inches) stud as awall supporting structure. Sheathing 1 had dimensions of 48 inches by 90inches (48″×90″). Sheathing 1 consisted of five layers with the firstlayer being a woven polypropylene scrim with a selvage tack. The secondlayer was made of a BYNEL® adhesive. The third and fifth layers weremade of high impact polystyrene. The second layer was located betweenthe first and third layers. The fourth layer was a polystyrene foam andwas located between the third and fifth layers. This is a similarstructure as shown above in FIG. 4. The following describes the testspecimens that were used in Example 1.

Example 1 Specimen Description

[0064] A. Materials

[0065] 1. Stud: 2×4, Stud Grade spruce pine fur (SPF) spaced at 16″ oncenter (o.c.)

[0066] 2. Top Plate: Single 1×4, Ungraded SPF

[0067] 3. Bottom Plate: Single 1×4, Ungraded SPF

[0068] 4. Gypsum: {fraction (5/16)}″ U.S. Gypsum, {fraction (5/16)}″National Gypsum or {fraction (5/16)}″ Georgia Pacific

[0069] 5. Siding: Georgia Pacific Parkside® D5 Vinyl Siding with anailing flange thickness of 0.038 inch.

[0070] B. Fastening

[0071] Top plate attached to studs with three (3)—{fraction(7/16)}″×1¾″×16 gauge (Ga.) Staples.

[0072] Bottom plate attached to studs with three (3)—{fraction(7/16)}″×1{fraction (3/4)}″×16 Ga. Staples.

[0073] Sheathing 1 fastened with 1″×1½″×16 Ga. staples at 3″ o.c. aroundperimeter and 3″ o.c. in the field.

[0074] In Zone II test samples, staples are 3″ o.c. in both centerstuds.

[0075] Gypsum fastened to frame with ¼″×1″×19 Ga. staples at 6″ o.c.around perimeter and no field fasteners.

[0076] Gypsum glued to frame with a ⅜″ bead of PVA glue on all framingmembers.

[0077] Siding fastened to sheathing into the studs with {fraction(7/16)}″×1½″×16 Ga. staples at 16″ o.c. per strip of siding.

[0078] C. Construction

[0079] The 48″×90″ test sample was first assembled with 2×4 studs thatwere 88.5 inches long. The top and bottom plates were 49.5 inches long.Polyethylene sheeting (6 mil) was placed between the 2×4 framing andSheathing 1. The framing was then squared with Sheathing 1 and fastenedas described above. The horizontal vinyl siding was fastened throughSheathing 1 into the studs. The {fraction (5/16)}″ gypsum was thenfastened to the opposite side of the frame as described above. Glue wasallowed to cure for 7 days before the testing began. Materials for theassemblies tested were commercially purchased products.

Example 1 Test Setup and Procedure

[0080] The testing was conducted in accordance with the ultimate loadtest procedures in H.U.D. Guide for Manufactured Home Standards Programs(9^(th) edition, December 1994) taken from §3280.401(b) of the FederalRegister. An 11-¼″ deep wood box was built 1″ wider and 1″ longer thanthe test sample. The top and bottom plates of the test samples weresecured to 2×4 ledgers. The test samples were placed horizontally on thetest fixture with the vinyl siding facing down, and the ledgers bearingon top of the wood box. The polyethylene sheeting (6 mil) that wasplaced between the wall framing and Sheathing 1 was sealed to the table.This allowed the entire surface of Sheathing 1 to be exposed to the fullnegative loads.

[0081] The uniform load was applied by evacuating the air below the testspecimen using a vacuum pump. The applied load was measured with a watermanometer capable of reading in 0.1 inch increments. The load wasapplied in approximate ¼ design live load increments at 10 minuteintervals until 1.25 times design load was reached. The load was thenincreased to 2.5 times design load or until failure occurred. The loadin inches of water column was converted to pounds per square foot (psf)by using the conversion of 1 inch (of water column) to 5.2 psf.

[0082] Deflections were taken using dial indicators capable of readingin 0.001″ increments. The deflections were taken at the quarter-pointsof the center stud.

Example 1 Results

[0083] A total of three specimens were tested for each specific gypsum({fraction (5/16)}″ U.S. Gypsum, {fraction (5/16)}″ National Gypsum or{fraction (5/16)}″ Georgia Pacific) for non-corner and comer Wind ZoneII requirements. The product sold by U.S. Gypsum Company that was usedwas {fraction (5/16)}″ Manufactured Housing Gypsum Baseboard. Theproduct sold by National Gypsum Company that was used was {fraction(5/16)}″ Gold Bond® Gypsum Wallboard. The product sold by GeorgiaPacific Corporation that was used was {fraction (5/16)}″ PreDeck® GypsumBoard. Experiments 1 and 2 used U.S Gypsum, Experiments 3 and 4 usedNational Gypsum, while Experiments 5 and 6 used Georgia Pacific. Theultimate load in pounds per square foot (psf) was determined inaccordance with H.U.D. Guide for Manufactured Home Standards Programs(9^(th) edition, December 1994) taken from §3280.401(b) of the FederalRegister. The ultimate load was taken for three specimens (S1, S2 andS3). The average of these three specimens is shown under the “AVG.”column. The results are as in Table 1. TABLE 1 EXPER. ULTIMATE LOAD(PSF) AVG. DEFLECTION NO. S1 S2 S3 (PSF) (PASS/FAIL) WIND ZONE 1 96.7296.72 95.68 96.37 PASSED II Non-Corner 2 120.64 121.68 122.72 121.68PASSED II Corner 3 95.68 96.72 97.76 96.72 PASSED II Non-Corner 4 121.68122.72 120.64 121.68 PASSED II Corner 5 95.68 98.8 97.76 97.41 PASSED IINon-Corner 6 120.64 121.68 124.8 122.37 PASSED II Corner

[0084] Each of the gypsums at the non-corner and corner conditions inExperiments 1-6 passed the deflection test for Wind Zone II. Inaddition, each of the gypsums at the non-corner and corner conditions inExperiments 1-6 satisfied the ultimate load for Wind Zone II. Theultimate load requirement for Wind Zone II for a non-corner condition is95 psf, while the ultimate load requirement for Wind Zone II for acorner condition is 120 psf.

Example 2

[0085] Negative wind pressure load tests were conducted on samples of48″×90″ Sheathing 1 (described above in Example 1) without a selvagetuck on the scrim layer using a 2×4 stud as a wall supporting structure.The following describes the test specimens that were used in Example 2.

Example 2 Specimen Description

[0086] A. Materials

[0087] 1. Stud: 2×4, Stud Grade SPF spaced at 16″ (o.c.)

[0088] 2. Top Plate: Single 1×4, Ungraded SPF

[0089] 3. Bottom Plate: Single 1×4, Ungraded SPF

[0090] 4. Gypsum: {fraction (5/16)}″ U.S. Gypsum

[0091] 5. Siding: Georgia Pacific Parkside® D5 Vinyl Siding with anailing flange thickness of 0.038 inch.

[0092] B. Fastening

[0093] Top plate attached to studs with five (5)—{fraction(7/16)}″×1¾″×16 Ga. Staples.

[0094] Bottom plate attached to studs with five (5)—{fraction(7/16)}″×1¾″×16 Ga. Staples.

[0095] Sheathing 1 fastened with 1″×1½″×16 Ga. staples at 3″ o.c. aroundperimeter and 3″ o.c. in the field.

[0096] Gypsum glued to frame with a ⅜″ bead of PVA glue on all framingmembers.

[0097] Siding fastened to sheathing into the studs with {fraction(7/16)}″×1½″×16 Ga. staples at 16″ o.c. per strip of siding.

[0098] C. Construction

[0099] The construction similar to that described above in Example 1.

Example 2 Test Setup and Procedure

[0100] The test setup and procedure were similar to that described abovein Example 1.

Example 2 Results

[0101] One specimen (S1) was tested using {fraction (5/16)}″ U.S. Gypsumfor non-corner Wind Zone III. The results are as follows in Table 2.TABLE 2 EXPER. ULTIMATE LOAD (PSF) AVG. DEFLECTION NO. S1 S2 S3 (PSF)(PASS/FAIL) WIND ZONE 7 99.84 N/A PASSING III Non-Corner

[0102] Experiment 7 did not pass the requirement for ultimate load underWind Zone III using 2×4 studs. Experiment 7 was not completed becausethe sheathing pulled over the staples. At the time when Experiment 7 wasstopped, specimen S1 was passing the deflection test for Wind Zone III.It is believed, however, that if Experiment 7 had continued, thenspecimen S1 likely would have not passed the deflection test for WindZone III.

Example 3

[0103] Negative wind pressure load tests were conducted on samples of48″×90″ Sheathing 1 (described above in Example 1) without a selvagetuck on the scrim layer using a 2×6 stud as a wall supporting structure.The following describes the test specimens that were used in Example 3.

Example 3 Test Specimen Description

[0104] A. Materials

[0105] 1. Wall Stud: 2×6, Stud Grade SPF spaced at 16″ (o.c.)

[0106] 2. Top Plate: Single 1×6, Ungraded SPF

[0107] 3. Bottom Plate: Single 1×6, Ungraded SPF

[0108] 4. Siding: Georgia Pacific Parkside® D5 Vinyl Siding with anailing flange thickness of 0.038 inch.

[0109] B. Fastening

[0110] Top plate attached to studs with five (5)—{fraction(7/16)}″×1¾″×16 Ga. Staples.

[0111] Bottom plate attached to studs with five (5)—{fraction (7/16)}:×1{fraction (3/4)}″×16 Ga. Staples.

[0112] Adhesive—Not used

[0113] Gypsum—Not used

[0114] Sheathing 1 fastened with 1″×1-¼″×16 Ga. Staples, Angled at 45degrees at 3″ o.c. in the field and 3″ o.c. around perimeter.

[0115] Siding fastened to sheathing into the studs with {fraction(7/16)}″×1½″×16 Ga. Staples at 16″ o.c. per strip of siding.

[0116] Construction

[0117] The construction similar to Example 1 except the studs in Example3 were 2×6. TABLE 3 EXPER. ULTIMATE LOAD (PSF) AVG. DEFLECTION NO. S1 S2S3 (PSF) (PASS/FAIL) WIND ZONE 8 171.6 N/A PASSED III Corner

[0118] Experiment 8 passed the requirement for ultimate load under acorner condition for Wind Zone III using 2×6 studs. Experiment 8 alsopassed the requirement for deflection under a corner condition for WindZone III using 2×6 studs.

Example 4

[0119] Two specimens of Sheathing 1 were tested for surface burning inaccordance with the procedure set forth in ASTM E 84/UL 723 (Test ForSurface Burning Characteristics of Building Materials). The firstspecimen had a flame spread rating of 0 and a smoke developed rating of20. The second specimen had a flame spread rating of 0 and a smokedeveloped rating of 75.

[0120] Sheathing 1 complied with H.U.D. Guide for Manufactured HomeStandards Programs (9^(th) edition, December 1994) taken from Section3280.207(a) 2.i of the Federal Register with respect to the flame spreadrating because the flame spread rating was 75 or less. Sheathing 1 alsocomplied with H.U.D. Guide for Manufactured Home Standards Programs(9^(th) edition, December 1994) taken from Section 3280.207(a) 2.i ofthe Federal Register with respect to the smoke developed rating becausethe smoke developed rating was 450 or less.

[0121] While the present invention has been described with reference toone or more particular embodiments, those skilled in the art willrecognize that many changes may be made thereto without departing fromthe spirit and scope of the present invention. Each of these embodimentsand obvious variations thereof is contemplated as falling within thespirit and scope of the claimed invention, which is set forth in thefollowing claims.

What is claimed is:
 1. A sheathing adapted to be fastened to at leastone wall supporting structure, comprising at least two layers: (a) afirst layer comprising a polymeric foam layer; and (b) a second layercomprising a polymeric scrim, said second layer being located adjacentto said first layer, said second layer having means for reinforcing itsperiphery so as to inhibit failure of the scrim.
 2. The sheathing ofclaim 1 further including a third layer comprising an adhesive, saidthird layer being located between said first and said second layers. 3.The sheathing of claim 1, wherein the means for reinforcing is a selvagetuck or a folded-over edge.
 4. The sheathing of claim 3, wherein themeans for reinforcing is a selvage tuck.
 5. The sheathing of claim 4,wherein said selvage tuck is located on at least two opposing portionsof the periphery of said second layer.
 6. The sheathing of claim 2further including a fourth layer being located adjacent to said secondlayer, said fourth layer comprising an impact polystyrene.
 7. Thesheathing of claim 6, wherein said impact polystyrene is a high impactpolystyrene.
 8. The sheathing of claim 6 further including a fifth layerbeing located adjacent to the third layer, said fifth layer comprisingan impact polystyrene.
 9. The sheathing of claim 1, wherein said firstlayer is a polyolefin foam.
 10. The sheathing of claim 1, wherein saidfirst layer is a polyethylene terephthalate foam.
 11. The sheathing ofclaim 1, wherein said first layer is a polystyrenic foam.
 12. Thesheathing of claim 1, wherein said polymeric scrim is made frompolyolefins, polyesters or nylon.
 13. The sheathing of claim 12, whereinsaid polyolefinic scrim is made from polyolefins, said polyolefinicscrim being made of polypropylene, polyethylene or a combinationthereof.
 14. The sheathing of claim 13, wherein said polymeric scrim ispolypropylene.
 15. The sheathing of claim 1, wherein said polymericscrim is polypropylene and said first layer is a polystyrenic foam. 16.The sheathing of claim 15 further including a third layer comprising anadhesive, said third layer being located between said first and saidsecond layers.
 17. The sheathing of claim I wherein said sheathing isclassified as a Wind Zone II material in accordance with H.U.D. Guidefor Manufactured Home Standards Programs (9^(th) edition, December 1994)taken from §3280.401(b) of the Federal Register.
 18. The sheathing ofclaim 17 wherein said sheathing is classified as a Wind Zone IIImaterial in accordance with H.U.D. Guide for Manufactured Home StandardsPrograms (9^(th) edition, December 1994) taken from §3280.401(b) of theFederal Register.
 19. The sheathing of claim 1, wherein said secondlayer is a woven polymeric scrim.
 20. The sheathing of claim 19, whereinsaid second layer is a cross-woven polymeric scrim.
 21. The sheathing ofclaim 1, wherein said second layer is a non-woven polymeric scrim.
 22. Amethod of using a sheathing in a building, said method comprising:providing a sheathing comprising at least two layers, the first layercomprises a polymeric foam layer, the second layer comprises a polymericscrim and is located adjacent to said first layer, said second layer hasmeans for reinforcing its periphery so as to inhibit the failure of thescrim; providing at least one wall supporting structure; and installingsaid sheathing to at least one of said wall supporting structures. 23.The method of claim 22, wherein the step of installing includes the useof a fastener.
 24. The method of claim 23, wherein said fastener is astaple or a nail.
 25. The method of claim 22, wherein the means forreinforcing is a selvage tuck or a folded over edge.
 26. The method ofclaim 25, wherein the means for reinforcing is a selvage tuck.
 27. Themethod of claim 26, wherein said selvage tuck is located on at least twoopposing portions of the periphery of said sheathing.
 28. The method ofclaim 27, wherein the step of installing said sheathing to at least oneof said wall supporting structures positions said selvage tuck in alocation that is generally parallel to said at least one wall supportingstructure.
 29. The method of claim 22, wherein the building isprefabricated housing or site built housing.
 30. A sheathing adapted tobe fastened to at least one wall supporting structure, comprising atleast three layers: (a) a first layer comprising a polymeric foam layer;(b) a second layer comprising a polymeric cross-woven scrim, said secondlayer having means for reinforcing its periphery so as to inhibit thefailure of the scrim; and (c) a third layer comprising an impactpolystyrene, said third layer being located between said first and saidsecond layers.
 31. The sheathing of claim 30 further including a fourthlayer comprising an impact polystyrene, said fourth layer being locatedadjacent to said first layer on an opposing side from said third layer.32. The sheathing of claim 31 further including a fifth layer comprisingan adhesive, said fifth layer being located between said second andthird layers.
 33. The sheathing of claim 30 further including a fourthlayer made of an adhesive, said fourth layer being located between saidsecond and third layers.
 34. The sheathing of claim 30, wherein saidpolymeric foam is a polyolefin foam.
 35. The sheathing of claim 30,wherein said polymeric foam is a polystyrenic foam.
 36. The sheathing ofclaim 30, wherein said polymeric foam is polyethylene terephthalatefoam.
 37. The sheathing of claim 30, wherein said woven scrim is a wovenpolypropylene scrim.
 38. The sheathing of claim 30, wherein said meansfor reinforcing is a selvage tuck.
 39. The sheathing of claim 30,wherein said polymeric foam is polystyrenic foam, said polymeric scrimis a woven polypropylene scrim and wherein said sheathing furtherincludes a fourth layer and a fifth layer, said fourth layer comprisingan impact polystyrene and is located adjacent to said second layer on anopposing side from said third layer and said fifth layer comprises anadhesive and is located between said second and third layers.
 40. Thesheathing of claim 39 further including a sixth layer comprising apolypropylene layer and a seventh layer comprising an adhesive, saidsixth layer being located adjacent to said first layer on an opposingside from said third layer, said seventh layer being located adjacent tosaid sixth layer on an opposing side from said first layer.
 41. Thesheathing of claim 30, wherein the thickness of the sheathing is fromabout 0.25 inch to about 1.0 inch.